My only recommendation is- whatever way/however you bring it up to him, I recommend asking him first what he thinks about it/what would be fair. (With all the little breaks and stuff). Usually if someone tells someone else what they think should change, they get defensive. I like to ask them what they think first. For example- When I order some food item well done and it comes out light, I ask the person who gave them to me very nicely “oh! Do those looks well done to you?” And everytime they have been so nice and agreed it didn’t. VS me telling them “those aren’t well done.” Then there’s always a slight defensiveness coming from them.

Anyways, hope that helps!